The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
The prevalence of infected cattle by
Trypanosoma spp. in Handeni
district and Ngorongoro
Conservation Area
Name: E.M. Bax
Supervisor: F.J.C.M. van Eerdenburg
Supervisors Tanzania: Z. Lyimo and F. Mramba
Date: March 2011
1
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
Index
p. 3
Abstract
p. 4
Introduction
p. 5
Trypanosomes
Morphology
Live cycle in cattle
Pathogenesis
Differentiation of important Trypanosoma species in cattle
p. 7
Materials & Methods
Study areas
Animals
Sampling method
Data analysis
Questionnaire
p. 9
Results
PCV results
Infection rate
Questionnaire
p. 11
Discussion
p. 13
Acknowledgements
p. 14
References
p. 15
Appendix
2
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
Abstract
Bovine trypanosomiasis is a disease caused by Trypanosoma spp. and transmitted by
tsetse flies (Glossina spp.). An infection with trypanosomes in cattle is responsible for
peaks of hyperthermia, anaemia, severe loss of meat and milk production, decreased
fertility and increasing calf mortality. Because of the high importance of livestock in
Tanzania in an economic, social and nutritional view, this disease is a major complication
for livestock owners.
This study about the prevalence of bovine trypanosomiasis was conducted in Handeni
district and Ngorongoro Conservation Area (NCA). During the months September until
November 202 animals in these two areas were tested on the presence of trypanosomes
by taking blood samples. The infection rate in Handeni district and NCAA was respectively
4.167% (3 positives in 72 samples) and 1.538% (2 positives in 130 samples). T. vivax was
found in the positive blood samples in Handeni district and T. congolense was detected in
NCA. Livestock owners in these areas treated 10% to 60% of their cattle with trypanosome
chemoprophylaxis. Due to this, the infection rate in non treated animals is expected to be
higher than the verified infection rate. Also the packed cell volume (PCV) of the blood
samples was measured. There was a significant difference (p=0,030 with α=0,05 )
between the PCV in cattle in these two districts. The cattle from NCA had a significant
higher PCV compared to the cattle in Handeni district. This can be caused by the poor
amount of water and food available in Handeni district.
The aim of this research project was to establish the prevalence of infections with
Trypanosoma spp. in cattle in two different areas in Tanzania, Handeni district and
Ngorongoro Conservation Area (NCA). By establishing the prevalence of trypanosomiasis,
the importance of prevention techniques in these areas is demonstrated.
3
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
Introduction
Bovine Trypanosomiasis is a disease caused by Trypanosoma spp. and transmitted by
tsetse flies (Glossina spp.). These vectors are responsible for the transfer of the protozoa
Trypanosoma spp. to livestock, wild animals and humans. These parasites have strict
hematophagous behaviour and have a preference for areas with many wild animals or
livestock. (1) This tsetse-associated disease is widely spread over 10 million km2 in subSaharan Africa. One third of this area contains rain forest and the remaining part is
covered with grassland. This area is under developed comparing to the rest of the world,
so there are less machines and livestock is used as a harnessed team. This emphasises the
importance of livestock in this area. (2)
Livestock is economically, socially and for nutrition and agricultural purposes very
important for the African population. Therefore, tsetse transmitted trypanosomiasis is
considered to be one of the major constraints to improve livestock production in subSaharan Africa. Approximately 46 million cattle in sub-Saharan Africa are exposed to
African animal trypanosomosis (AAT). In Tanzania tsetse flies occupy up to two third of the
country. Because of the transmission of the protozoa Trypanosoma spp., tsetse flies have
a great influence on food production, natural-resource utilization and the pattern of human
settlement in this region.(1)(3)(4) Decades ago the natural habitat of the tsetse fly was
wild animals. Because of the deforestation, loss of biodiversity and erosion, numbers of
wild animals are decreasing. The increasing cattle population and the decreasing wild life
population were responsible for the interest of the tsetse fly for cattle instead of wildlife.
(1) In livestock, Trypanosoma congolense, Trypanosoma vivax and Trypanosoma brucei
brucei, are the main causes for trypanosomiasis.
Some animals, like many wildlife species, are trypanotolerant, which means they won’t
have any discomforts during a trypanosomiasis infection. Other animals, like most
domestic cattle, are trypanosusceptible, and will become ill during an infection with
trypanosomes. (5) The symptoms of trypanosomiasis in cattle differ with the grade of
illness. There are three grades that can occur during the disease; acute, sub-acute and
chronic. The last one is by far the form that occurs the most. In outline, the most common
symptoms are fever, anaemia, severe loss of meat and milk production, decreased fertility
and increased calf mortality. (4) In chronic cases the cattle are extremely emaciated, the
coat is in poor condition and the hair of the tail switch can be completely absent. Due to
the anaemia, the mucous membranes are very pale, breathing is laboured and the cow has
a rapid pulse. The combination of these effects can cause sudden death. (6)
Tanzania counts approximately 14 million cattle according to the census of the National
Bureau of Statistics in 2002 and 82.1% of the residents are working in the agricultural
business in 2000/01. As a result this disease is causing problems for many Tanzanian
residents.
Therefore, bovine trypanosomiasis can cause serious health and welfare problems in
combination with tremendous economical losses for the farmers.
The aim of this research project is to establish the prevalence of infected cattle by
Trypanosoma spp. in two different areas in Tanzania, Handeni district and Ngorongoro
Conservation Area (NCA). When this study results that trypanosomiasis has still a high
prevalence, the importance of prevention techniques in these areas is demonstrated.
Trypanosomes
Morphology
The protozoa Trypanosoma contains several species which can
be distinguished by morphological differences. The different
species can be categorized in two groups; the salivaria and
stercoraria. The main species found in cattle causing
trypanosomiasis are T. congolense, T. vivax and T. brucei
brucei. These species belong to the salivaria group. The size
Fig. 1: Trypanosoma brucei
of this parasite varies from 8 to over 50 µm. The cytoplasm
in a bloodsmear (7)
of this unicellular organism is protected by the pellicle, a cell
membrane. This pellicle is very flexible so it allows body
movement, while the parasite retains its normal shape. In the cytoplasm various
structures are present. The nucleus is a very prominent structure which is functioning as
the command centre of the organism. Granules in the cytoplasm can sometimes be seen
and they function as nuclear or food reserves. Occasionally the granules are caused by a
4
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
5
reaction between the trypanosome and the immune system of the host. At the posterior
end of the trypanosome a kinetoplast is seen. This kinetoplast varies in size and position
by the different trypanosome species. The kinetoplast has an important role in the
reproduction en metabolism of the unicellular organism. The role of the kinetoplast in the
cyclical transmission by tsetse flies is still not clear but probably essential. Adjacent to this
kinetoplast a parabasal body is present on which a flagellum arrises. The flagellum
contains the length of the parasite and has an elongation at the end where it becomes a
free flagellum. During the length of the flagellum parallel to the cell an undulating
membrane, which contains of pellicle and cytoplasm, is attached to these structures as
shown in figure 2. The undulating membrane is also a structure with which it is possible to
identify the different trypanosome species, even as the length and shape of this unicellular
organism. (2)
Fig. 2: Diagram of a trypanosome (2)
Live cycle in cattle
Infective metatrypanosomes, which develop in the intestines of
the tsetse fly, are injected by the proboscis of the tsetse fly in
the skin of the host animal. These metatrypanosomes multiply
and develop at the injection site where some red swollen
headed tissue, known as chancre, can be seen. From there the
mature trypanosomes (trypomastigotes) are absorbed by
lymph tissue and released in the bloodstream. The nutrition of
Fig. 3: Tsetse fly, the arrow
the trypanosomes in the host animal are fats, proteins and
shows the proboscis (8)
carbohydrates from the body fluid of the animal absorbed and
digested by enzyme systems of the parasite. (2) In the
bloodstream, lymph fluid and spinal fluid the trypomastigotes multiply by binary fission
(division into two daughter cells). When a tsetse fly absorbs these trypomastigotes from
the host animal, it can infect other animals. (9)
Pathogenesis
Trypanosomes have specific proteins on their surface which stimulate the host animal to
produce antibodies against these proteins. As a reaction on this defense system the body
temperature increases and a hyperthermia occurs. The specific antibodies destroy almost
all the trypanosomes after a few days and the temperature of the host animal will
decrease. Despite this, a few trypanosomes will be able to replace their surface proteins so
the specific host antibodies can not attack them. As a result these trypanosomes will
survive and are able to multiply. So again they can cause a parasitaemia with the clinical
symptom hyperthermia. The trypanosomes are able to produce infinite new surface
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
proteins so this process is continuous. This explains the specific temperature curve during
this infection with hyperthermia peaks every few days. Another clinical sign of
trypanosomiasis is anaemia which has in principle two different pathological processes. In
the early stage of the infection the surface proteins of the lysed trypanosomes can attach
to red blood cells which trigger the phagocytes of the host to remove them. In the
chronical stage of trypanosomiases it is believed that toxines produced by the parasites
suppress the haemopoietic system. By this, the production of new red blood cells is
decreased which also can cause the anaemia. (2) The reduced amount of red blood cells
results in a decreased packed cell volume (PCV). When there is a serious parasitaemia, the
PCV is very low. (6)
Immunosuppression is another symptom of trypanosomiasis which probably is a result of
the depressed haemopoietic system. The haemopoietic system normally produces white
blood cells that are part of the immune system. In the acute stage the immune system is
overruled by reacting on the parasitaemia, so an accurate immune reaction on secondary
infections is reduced.
Differentiation of important Trypanosoma species in
cattle
T. brucei brucei is the most important species of the
salivaria trypanosomes. This one is not infectious for
humans. T. brucei brucei is pleiomorphic and exist in a
long and thin form and in a short and stumpy form. The
long and thin form is on average 29 µm and contains a
free flagellum. The short and stumpy form is on
average 18 µm and the free flagellum is short or
absent. The kinetoplast is small and located at the
posterior end of the trypanosome. At the long thin form
the nucleus is centrally located, while the position of
the nucleus in the short and stumpy form can differ.
The undulating membrane is in both forms conspicuous
and the posterior end is pointed. (2,10)
Fig. 4: Trypanosoma brucei
brucei (2)
T. congolense is a small
parasite, 8 to 20 µm, and has a
inconspicuous and poorly
developed undulating
membrane, a medium-sized
kinetoplast and a blunt posterior
end. There is no free flagellum
present in this species and the
nucleus is located centrally.
(2,10)
Fig. 5: Trypanosoma congolense
(2)
T. vivax is ranging from 20 to 27 µm and has a
large kinetoplast which is extremely posterior
located in the rounded posterior end. The
nucleus is again centrally placed. There is a
short free flagellum present and the undulating
membrane is inconspicuous. Most of the
cytoplasm is located posterior from the nucleus
and as a result, that part is a little bit swollen.
(2,10)
Fig. 6: Trypanosoma
vivax (2)
6
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
7
Materials & Methods
Study areas
Two different areas in Tanzania were selected for blood sampling. The first area is Handeni
district, which is situated in north-eastern Tanzania, 217 km from Dar es Salaam with an
altitude of 756 m (Coordinates: 5° 30′ 0″ S and 38° 0′ 0″ E). In this area local farmers
and Maasai (semi-nomadic people) are living together with their livestock. The total
population of Handeni is 248.633 according to the 2002 census. The second area was the
Ngorongoro Conservation Area (NCA), which is a National Park that covers 8.292 square
kilometers and varies in altitude from 1020-3578 m. This park is situated in the north of
Tanzania, 180 km west of Arusha with an average altitude of (3° 12′ 32″ S,
35° 27′ 46″ E). In this conservation area Maasai and wild animals (approximately 25.000
large animals) are living together. (11)
This study was done in the months September, October and November, so it started in the
cool dry season and ended in the short rainy season. Both of these areas have sparse
vegetation and minor water sources. Therefore the quantity of food and water for the
livestock is limited.
Animals
For this study 202 cows, crossbreds of local African breeds (Zebu and Boran), of both
sexes were sampled. In Handeni and in the Ngorongoro Conservation Area were
respectively 72 and 130 cattle tested. In the first area, Handeni district, the cattle
belonged to local farmers and Maasai and in the second area, NCAA, the cattle belonged to
Maasai. The farmers were able to choose the tested animals which is clarified in the
discussion. The animals differ in age from 0.5 year to 12 years old and were divided in 2
different groups. Group 1 is called ‘young’ which contain the animals in an age between 0
and 1.5 year. Group 2 is called ‘adult’ and contains all the animals older than 1,5 years.
These groups included respectively 57 (28.2%) and 145 (71.8%) cows. The percentage
female cows in Handeni district and NCAA are respectively 77.8% and 71.5%.
Sampling Method
The cattle are sampled by collecting blood from the ear veins in 8 cm heparinized capillary
tubes from TT3TM (Top-Tech Biomedicals) and by making thin and thick blood smears
which were well stored in a cool box (CosmoPlast™) on 5.5 degrees Celsius. The capillary
tubes were properly sealed with crystaseal (Hawksley™) for blood packed cell volume
(PCV) analysis. In the laboratory the capillary tubes were centrifuged and the PCV was
read by a PCV reader (Hawksley™). After the centrifugation the buffy coat was collected by
cutting the coat/plasma junction with a diamond-tipped pencil. The buffy coat was put on
an objective glass and covered with a cover slip. After this the buffy coat can be screened
on trypanosomes by using a microscope at magnification of x100 and oil emersion. (12)
The blood smears were fixed with methanol and stained with 10% Giemsa coloring for 45
minutes so they could be screened easily for trypanosomes with a microscope. As a result
of the Giemsa coloring, the possible present protozoa changes color so they can be
recognized better. This method is called the Standard Trypanosome Detection Methods
(STDM) as described by Nonga and Kambarage. (4)
Data analysis
The data of this study was outlined in 8 groups as shown in figure 6. Group 1 to 4 contain
data from the area Handeni and group 5 to 8 contain data from the Ngorongoro
Conservation Area.
Handeni
Ngorogoro
Female
Young
Male
Adult
Group 1
Young
Group 2
Female
Adult
Group 3
Young
Group 4
Fig. 6: The spreading of the data in groups
Male
Adult
Group 5
Young
Group 6
Adult
Group 7
Group 8
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
All data is managed in SPSS16 database which is also used for the statistical analyses. In
this study it is expected that the PCV data has a normal distribution with a significance
level of 5% (α=0.05) because same researches in other areas could prove this postulate.
(5) The One-Sample Kolmogorov-Smirnov Test (α = 0.05) was used to look if there is a
normal distribution in the PCV. All the groups had a normal distribution except group 2
(Exact Sig. = 0.047), therefore the data are transformed with Log(PCV+5). The
transformation accomplished a normal distribution in all the groups. Also the mean, SD
and P values of the PCV in the different groups is analyzed by SPSS16. The PCV difference
between areas and sexes is tested with the Levenes test.
Questionnaire
There was a questionnaire available with questions about livestock production and about
the knowledge on the presence of tsetse flies. In the appendix the questionnaire is
enclosed. Unfortunately it was not possible to ask these questions to all the farmers
because of the language barrier. This questionnaire is, therefore, only used in Handeni
district.
8
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
Results
PCV results
Group 2 didn’t have a normal distribution (Exact Sig. = 0.047), therefore all PCV data are
transformed with Log(PCV+5) for the statistical analysis. Graphic 1 shows the PCV amount
of the different groups.
40
35
30
PCV
25
Handeni
20
NCA
15
10
5
0
♀ Young
♀ Adult
♂ Young
♂ Adult
Animal groups
Graphic 1: PCV of the different groups. The PCV of the groups in NCA is significant higher
compared to the PCV of the groups in Handeni district.
The group with young animals includes animals from 0-2 years old. The adult group
includes animals above 2 years old.
There is a significant difference in the PCV (p=0,030 with α=0,05 ) between the area’s and
sexes according to the Levenes test. The cattle from NCA had a significant higher PCV
compared to the cattle in Handeni district. This result is probably caused by the amount of
food and water in this area. Handeni district is a very dry area with less food and water,
instead of NCA where there are more water sources. The tested bulls, especially in
Handeni district, had a lower PCV comparing to the PCV of the cows in this area. This is
probably due to a small group of bulls (22,2%) comparing to the cows (77,8%) and to a
young group of bulls; 5 from the 7 adult bulls in Handeni district were 2 years old. In table
1 the mean, standard deviation and P values of the PCV of the different groups are shown.
Handeni
Female
Male
P value NCA
P value
Young
26,63 ± 4,475
0,829
30,58 ± 3,895
0,902
Adult
27,03 ± 5,121
0,094
29,07 ± 3,976
0,06
Young
22,78 ± 5,239
0,824
29,60 ± 4,624
0,93
Adult
23,33 ± 5,502
0,976
28,96 ± 4,311
0,988
Table 1: Mean and SD with the P values of the different groups
The P value is from the transformed data
Infection rate
In the 202 sampled animals, there are 5 cows found (2.475%) which were positive on
trypanosomiasis. The infection rate in Handeni district and NCA was respectively 4.167%
(3 positives in 72 samples) and 1.538% (2 positives in 130 samples). In the following
table, the infection rate of the different groups is shown.
9
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
Female
Male
Young
Adult
Young
Adult
Total
Handeni
0/21 (0%)
1/35 (2.857%)
1/9 (11.111%)
1/7 (14.286%)
3/72 (4,167%)
NCAA
1/15 (6.667%)
1/78 (1.282%)
0/12 (0%)
0/25 (0%)
2/130 (1,538%)
Table 2: Percentage infected animals in the different groups
T. Congolense is verified twice in NCA and T. Vivax is verified three times in Handeni
district. In Handeni district there was one adult bull positive on T. vivax. This bull had no
clinical signs of Trypanosomiasis and was not treated against this disease.
Questionnaire
In the Handeni district a questionnaire is used to look after the treatment and livestock
holding at 10 farms. It was impossible to ask these questions in NCA because of the
language barrier. The results of this questionnaire were firstly that in spite of
trypanosomiasis the farmers also had to deal with anaplasmosis, east coast fever and
babesiosis. Tickborn diseases are still a big problem in Africa. All the farmers treat on
average 10% to 60% of their animals against trypanosomes every month. The treatment
is based on clinical signs, so they are not sure that the animals are actually suffering from
trypanosomiasis or the clinical signs are caused by another disease.
The chemoprophylaxis they use are Berenil, Samorin and Novidium.
The presence of trypanosomiasis transmitted by the tsetse fly was known by every farmer
and they suggested to the government to place more dipwash-tanks (bath with acaricide)
and water sources.
10
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
Discussion:
During this study, blood of cattle was tested for an infection with the protozo
Trypanosoma. The infection rate in the two different areas was 2.5% which is almost equal
to the infection rate verified by Nonga and Kambarage (2009) in southern Tanzania
(2,3%). Connor and Halliwell (1987) reported a prevalence of 16% in southern Tanzania.
This big difference is likely due to the regular use of chemoprophylaxis. However,
trypanosomiasis is not always diagnosed. The farmers treat their cattle with clinical signs
with trypanosome chemoprophylaxis. The medicines they use are Samorin, Berenil and
Novidium. Samorin is a preventive drug which has a long acting time of 3 months. Berenil
and Novidium are both curative drugs which are working for 2 weeks.
As a result of the regular use of these medicines, it was not possible to determine
trypanosomes in these cattle. However, the absence of trypanosomes in the blood samples
doesn’t mean that there are less infected animals.
The frequent use of these chemoprophylaxis can induce drug resistance in this area. In
other districts in East Africa the resistance is proven. (3)
During this study the farmers were able to choose the animals to be sampled. They were
curious about the effect of the treatment, so most of the tested animals were treated. To
give a legitimate infection rate in these areas, not treated animals should be chosen at
random. Still the farmers assume that trypanosomiasis is a big problem in their livestock,
but to prove this, the research should be done once again with not treated animals.
In Handeni district and NCA a few dipwash-tanks with acaricide were established by the
government for the farmers to prevent diseases caused by ticks and flies. The dipped
animals had less ticks and flies on their skin. Probably because of the dipwash-tanks the
tsetse population in these areas is decreased. According to the study about the prevalence
of tsetse flies in Handeni district and NCA by van der Geest it was concluded that there
was a significant lower amount of flies in areas with a dipwash-tank, comparing to areas
where these acaricide baths are not available. (13)
The materials and methods that were used could be improved by using EDTA blood tubes
instead of capillairy tubes. The capillairy tubes are very fragile and some of them were
broken during the drive to the laboratory. As a result it was not possible to make a buffy
coat and to verify the PCV of that animal. When using blood tubes it is also easier to
sample the blood from the tail vein instead of the ear vein.
Another problem during the study was communication with Maasai people. This was
difficult because of the language barrier. As a result not all the questions in the
questionnaire are answered especially in NCA.
Tsetse flies can also infect humans with trypanosomiasis as it is a zoonotic disease. In this
study specific cattle sensitive trypanosomes are verified, which rarely cause
trypanosomiasis in humans. During this study another study was done in the same areas
to verify the prevalence of infected tsetse flies. There are respectively 219 and 156 flies
dissected in Handeni district and NCA. In Handeni district 4,5% of the tsetse flies were
positive on trypanosomes and a prevalence of 2,7% was found in NCA. In Handeni district
only T. vivax was found which is similar to the parasites found in the blood of the cattle in
this district. In NCA T. vivax, T. brucei and T. congolense was found in the flies. (13) This
is different from this study because in the infected cattle in NCA only T. congolense was
found.
The PCV reference for cattle is 24-48 %. (14) According to this reference the PCV of the
males in Handeni district is too low and generally the PCV in all the groups is quite low.
This is probably a result of a cured infection with trypanosomes which is treated by the
farmers. The samples are not positive because of phasing out the protozoa by the
treatment.
At this time there are several projects going on to eliminate the tsetse fly in Tanzania. One
of these projects is the Sterile Insect Technique (SIT). In this technique male tsetse flies
are bred and sterilized and finally released in a specific area. By the sterilization of the flies
the multiplication in the field is reduced. (15) In Zanzibar this method is applied and the
result was a complete eradication of the tsetse fly. To eradicate the tsetse fly in the
mainland this same method is being used.
11
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
In conclusion, bovine trypanosomiasis is still a common disease in Tanzania. It is hard to
determine the actual infection rate because of the general use of trypanosome
chemoprophylaxis, but despite this, infected cattle are still found. The techniques to
eradicate the tsetse fly in these areas are very important to control this problem.
12
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
Acknowledgements
This research is completely assisted by the ‘Tsetse and Trypanosomiasis Research
Institute’ in Tanga. Especially I would like to acknowledge dr. F. Mramba and the experts
from the research institute. Furthermore I would like to thank dr. Z. Lyimo who arranged
the contact with the institute. My last acknowledge will go to all the livestock owners in
Handeni district and NCAA for the use of their animals in this research.
13
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
References
(1) Bossche Pvd, Rocque Sdl, Hendrickx G, Bouyer J. A changing environment and the
epidemiology of tsetse-transmitted livestock trypanosomiasis. Trends Parasitol
2010;26(5):236-243.
(2) FAO. A field guide for the diagnosis, treatment and prevention of African animal
Trypanosomosis. 1998.
(3) Efrem DB, Yacob HT, Hagos AT, Basu AK. Bovine trypanosomosis in Gimbi district of
Western Oromia, Ethiopia. Animal Biology 2010;60(2):123-131.
(4) Nonga HE, Kambarage DM. Prevalence of bovine trypanosomosis in Morogoro,
Tanzania. Pakistan Journal of Nutrition 2009;8(3):208-213.
(5) Gachohi JM, Bett B, Murilla GA. Factors influencing prevalence of trypanosomosis in
Orma Boran (Trypanotolerant) and Teso zebu (Trypanosusceptible) crosses in Teso
District, western Kenya. Bulletin of Animal Health and Production in Africa
2009;57(4):327-338.
(6) Connor RJ, Bossche Pvd. African animal trypanosomoses. In: Coetzer JAW, Tustin RC,
editors. Infectious diseases of Livestock. 2nd ed.; 2004. p. 251.
(7) Lukes J. Trypanosoma Gruby 1843. 2009. http://tolweb.org/Trypanosoma/98034
(8) Knols B. The dreaded tsetse fly. 2009; .
http://www.google.nl/imgres?imgurl=http://www.planyoursafari.com/wpcontent/gallery/article-photos/tsetse-witharrow.jpg&imgrefurl=http://planyoursafari.com/blog/the-dreaded-tsetse-fly/&usg=__aBermGCZig2bph88UYE0IiHAeM=&h=160&w=289&sz=20&hl=en&start=2&zoom=1&um=
1&itbs=1&tbnid=fo5k5MjdXiGNlM:&tbnh=64&tbnw=115&prev=/search%3Fq%3Dthe%2Bd
readed%2Btsetse%2Bfly%26um%3D1%26hl%3Den%26biw%3D1004%26bih%3D612%2
6tbm%3Disch&ei=mv7cTeOaD4qbOqvbkOgO
(9) Centers for Disease Control and Prevention. Parasites - African Trypanosomiasis. 2010.
(10) Taylor MA, Coop RL, Wall RL. Parasites of cattle. Veterinary Parasitology. third ed.:
Blackwell Publishing Ltd; 2007.
(11) NCAA. Discover the Ngorongoro Conservation Area. 2010; .
http://www.ngorongorocrater.org/
(12) Stein J, Ayalew W, Rege E, Mulatu W, Lemecha H, Tadesse Y, et al. Trypanosomosis
and phenotypic features of four indigenous cattle breeds in an Ethiopian field study. Vet
Parasitol 2010 Dec 25.
(13) Geest Mvd. The prevalence of African animal trypanosomiasis in Handeni district and
Ngorongoro conservation area. 2011; Thesis Faculty of Veterinary Science, University
Utrecht
(14) University of Minnesota. Guidelines for Collection of Blood from Experimental Animals.
2006; http://www.ahc.umn.edu/rar/blood.html
(15) Qian Jihui. Eradicating the Tsetse Fly on Zanzibar Island. 1997; International Atomic
Energy Agency, Austria. http://tc.iaea.org/tcweb/publications/factsheets/tsetse2.pdf
14
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
Appendix:
Questionnaire:
A: Household information
Village:
Ward:
Division:
District:
Name of respondent:
Family size:
Age of respondent:
Sex of respondent:
Education:
B: Livestock production information
Do you have cattle?
How many cows do you have?
What are the common diseases, which affect your cattle?
How many animals are treated against Trypanosomiasis?
How many animals die from Trypanosomiasis?
What kind of drugs do you use in the treatment?
How much do they cost?
What is your income per year?
C: Knowledge on the presence of tsetse fly
Do you know tsetse fly?
What do they cause?
What types of drugs do you use in treating your cattle?
If yes, where are they found and where do you meet them?
What are your main activities?
How frequently do you contact the flies?
A) Rare
B) Several time
What control methods do you use against flies?
D: Suggestion
What do you need from the government in order to solve the problem?
What do the village/ward/district do to overcome the problem?
15
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
16
Data:
Village
Enduleni
Enduleni
Enduleni
Enduleni
Enduleni
Enduleni
Enduleni
Enduleni
Enduleni
Enduleni
Enduleni
Enduleni
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Esirwa
Enduleni-Ndutu
Enduleni-Ndutu
Enduleni-Ndutu
Enduleni-Ndutu
Enduleni-Ndutu
Enduleni-Ndutu
Enduleni-Ndutu
Sex
Female
Female
Male
Male
Male
Male
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Male
Male
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Male
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Male
Female
Age
Adult
Adult
Adult
Adult
Adult
Adult
Young
Young
Adult
Adult
Adult
Young
Adult
Adult
Young
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Young
Young
Adult
Adult
Adult
Young
Adult
Adult
Adult
Adult
Adult
Young
Adult
PCV
33
24
34
28
29
30
30
34
28
30
31
34
28
26
25
Buffy
Coat
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
27
29
23
28
30
22
29
28
25
23
30
24
25
25
28
30
31
33
30
28
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
35
32
33
34
30
negative
negative
negative
negative
negative
29
32
negative
negative
Blood Smear
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
Enduleni-Ndutu
Enduleni-Ndutu
Enduleni-Ndutu
Enduleni-Ndutu
Enduleni-Ndutu
Enduleni-Ndutu
Enduleni-Ndutu
Enduleni-Ndutu
EnduleniEmbaruai
EnduleniEmbaruai
EnduleniEmbaruai
EnduleniEmbaruai
EnduleniEmbaruai
EnduleniEmbaruai
EnduleniEmbaruai
EnduleniEmbaruai
EnduleniEmbaruai
EnduleniEmbaruai
EnduleniEmbaruai
EnduleniEmbaruai
EnduleniEmbaruai
EnduleniEmbaruai
EnduleniEmbaruai
EnduleniEmbaruai
EnduleniEmbaruai
EnduleniEmbaruai
Kakesio
Kakesio
Kakesio
Kakesio
Kakesio
Kakesio
Kakesio
17
Female
Female
Female
Female
Female
Female
Female
Female
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
32
36
30
30
31
30
30
31
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
Female
Young
24
negative
negative
Female
Young
Male
Young
27
negative
negative
Male
Adult
38
negative
negative
Female
Adult
Male
Adult
23
negative
negative
Male
Adult
25
negative
negative
Male
Adult
Female
Adult
Female
Adult
Male
Young
Female
Adult
negative
Female
Young
negative
Male
Adult
21
negative
negative
Female
Adult
30
negative
negative
Male
Adult
25
negative
negative
Female
Adult
22
negative
negative
Female
Male
Male
Male
Female
Female
Female
Female
Adult
Young
Adult
Adult
Adult
Adult
Adult
Adult
25
negative
23
28
32
25
31
29
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
28
negative
negative
negative
25
negative
negative
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
Kakesio
Kakesio
Kakesio
Kakesio
Kakesio
Kakesio
Kakesio
Kakesio
Kakesio
Kakesio
Kakesio
Kakesio
Kakesio
Kakesio
Kakesio
Olpiro
Olpiro
Olpiro
Olpiro
Olpiro
Olpiro
Olpiro
Olpiro
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Male
Female
Male
Female
Female
Female
Female
Female
Male
Male
Female
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Young
Young
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Young
Olpiro
Olpiro
Olpiro
Olpiro
Olpiro
Olpiro
Olpiro
Engaruka
Engaruka
Engaruka
Engaruka
Engaruka
Engaruka
Engaruka
Engaruka
Engaruka
Engaruka
Engaruka
Engaruka
Nayobi
Nayobi
Nayobi
Nayobi
Nayobi
Nayobi
Male
Female
Female
Male
Male
Female
Female
Male
Male
Male
Male
Female
Female
Female
Male
Female
Male
Male
Male
Female
Female
Male
Female
Female
Female
Adult
Adult
Adult
Young
Young
Young
Young
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Adult
Young
Young
Adult
Adult
Young
Adult
Adult
Adult
Adult
32
30
31
22
38
23
29
34
32
24
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
18
28
26
25
41
29
30
27
31
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
34
24
23
23
28
31
26
25
33
27
35
34
32
30
33
34
31
38
32
33
35
30
34
24
32
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
positive (T. congolense)
negative
positive (T. congolense)
negative
negative
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
Nayobi
Nayobi
Nayobi
Nayobi
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
Female
Male
Male
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Male
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Female
Male
Female
Female
Male
Female
Female
Female
Female
Young
Young
Young
Adult
Adult/4jr
Adult/8jr
Young/1jr
Young/1jr
Young/1jr
Young/1jr
Adult/7jr
Adult/15jr
Young/7mnd
Adult/2jr
Young/1jr
Young/1jr
Young/1jr
Adult/2jr
Adult/11jr
Adult/6jr
Adult/8jr
Adult/2jr
Young/1,5jr
Adult/3jr
Young/1jr
Young/1,5jr
Adult/12jr
Young/1jr
Adult/9jr
Adult/4jr
Adult/5jr
Young/1jr
Young/9mnd
Adult/8jr
Adult/2jr
Adult/9jr
Young/1jr
Adult/5jr
Adult/3jr
29 negative
28 negative
36 negative
30 negative
22 negative
23 negative
21 negative
20 negative
34 negative
26 negative
25 negative
23 negative
27 negative
32 negative
30 negative
24 negative
28 negative
37 negative
washed
25 negative
34 negative
36 negative
37 negative
41 negative
28 negative
washed
25 negative
washed
22 negative
34 negative
24 negative
22 negative
18 negative
27 negative
29 negative
22 negative
24 negative
washed
25 negative
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
Male
Male
Female
Female
Female
Male
Male
Female
Male
Adult/6jr
Young/1jr
Adult/9jr
Adult/12jr
Adult/12jr
Adult/2jr
Adult/2jr
Adult/6jr
Adult/2jr
washed
28 negative
27 negative
25 negative
washed
16 negative
19 negative
26 negative
22 negative
19
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
positive (T. vivax en misschien T.
congolense)
negative
negative
negative
negative
negative
negative
negative
negative
The prevalence of infected cattle by Trypanosoma spp. in Handeni district and
Ngorongoro Conservation Area
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
(handeni)
Male
Female
Male
Female
Female
Female
Male
Male
Female
Male
Female
Female
Female
Male
Female
Female
Female
Female
Female
Female
Female
Female
Female
Male
Male
Female
Female
Female
Young/1jr
Young/1jr
Young/1jr
Young/9mnd
Adult/12jr
Adult/5jr
Young/1jr
Young/1jr
Young/1jr
Young/1,5jr
Young/1jr
Adult/5jr
Young/0.5jr
Adult/4jr
Adult/7jr
Adult/9jr
Adult/6jr
Adult/7jr
Adult/4jr
Young/1jr
Adult/2jr
Young/1jr
Adult/3jr
Adult/2jr
Young/0,5jr
Young/1jr
Adult/4jr
Adult/3jr
20
27
21
26
26
29
16
30
28
20
30
34
25
30
24
25
26
24
23
29
24
29
24
24
18
25
20
31
negative
negative
negative
negative
negative
negative
positive
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
positive
negative
20
negative
negative
negative
negative
negative
negative
positive T. vivax (thick smear)
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
negative
positive T. vivax (thick smear)
negative